Project Summary Exposure to smoke from cooking fires is among the top five causes of DALYs and death globally, and in Africa in particular. Our proposed study evaluates the associations between household air pollution (HAP), extracellular vesicle (EV) ? packaged microRNAs, and lung function. Our preliminary data show that lung function at age one-month correlates with HAP exposures in utero. These results need to be substantiated with mechanistic studies to help understand biology?which is necessary to prove causation?and identify possible molecular targets and biomarkers for future preventative efforts. We propose to build on an existing birth cohort in Ghana ?the Ghana Randomized Air Pollution and Health Study, or GRAPHS ? to assess the role of EV- packaged microRNAs in mediating the association between in utero HAP exposure and lung function. This work will build capacity in laboratory methods and air pollution exposure assessment, and lay the foundation for a future multicenter study of noncommunicable disease. Understanding mechanisms linking prenatal HAP exposure and the programming of future respiratory disease is of global importance given the enormous associated burden of disease. In the long run, our research may allow a simple cord blood test to identify those at increased risk, allowing focused interventions to optimize future lung health.